1. Field of the Invention
This invention generally relates to tea making and a method of extracting liquid tea from tea leaves using an automated tea maker.
2. Discussion of the Prior Art
There are two types of commercial tea makers: tea leaf makers that use tea leaves that are placed atop an open filter paper at the bottom of a brew basket and ground tea makers that use ground tea contained in preselected closed filter envelopes that arc placed in the bottom of the brew basket. In the case of the tea leaves, the tea leaves come in preselected amounts that are sealed in plastic packages to keep the tea leaves fresh until use. When it is time to use the tea leaves, a fresh cup-shaped filter paper is placed into a brew basket, the plastic package is opened and the tea leaves are dumped onto the bottom of the filter at the bottom of the brew basket. In the case of the ground tea makers, there is no need for a separate filter for the brew basket because the ground tea is already contained within an envelope made of filter paper. When it is time to use the ground tea, the envelope with the ground tea is simply placed into the bottom of the brew basket by itself
In both types of tea makers, after the dry tea ingredient has been located in the bottom of the brew basket, hot water is added into the open top of the brew basket at a sufficient rate compared to the liquid output rate of tea extract draining from the drain hole at the bottom of the brew basket to completely submerge the tea and to maintain the tea ingredient submerged for several minutes. As seen if FIG. 1, the brew basket 18 of a PRIOR ART tea maker has an open top 20, a small drain opening 22 and has an insert 24 within which is fitted a correspondingly shaped filter bag, or ground tea envelope, 26 made of filter paper and containing two ounces of ground tea. The known tea makers quickly add hot brew water 28 into the open top 20 to a level 30 that is well above the level of the tea in the filter bag 26. After all of the tea is submerged the known tea makers continue to add hot brew water as the tea extract slowly drains from the drain hole 22 to keep the tea submerged for several minutes.
A snug fit between the filter envelope 26 and the insert 24 within which it is nestled is designed to prevent the tea envelope from rising to the surface of the water 28. The diameter of the drain hole 22 is only approximately 0.115 inch to provide a relatively slow drain to enable the hot brew water to quickly accumulate within the brew basket and rise to the maximum level 30. After the hot brew water has reached the top level 30, the tea remains submerged while the extract slowly drains from the drain hole 22 over a period of several minutes.
Because the brew basket must contain at one time a substantial portion of the total hot brew water that is used, approximately seventy to eighty ounces per 1-xc2xd gallon of tea to be made, the brew basket must have a relatively large capacity and a relatively high profile. It is believed that all known commercial makers operate on the basis of steeping the tea in order to obtain the liquid tea extract.
After the teas is extracted, the liquid tea extract is passed into a dispensing or serving urn in which it is diluted with an amount of mixing water equal to make 1-xc2xd gallons, 3 gallons and 4-xc2xd gallons of tea. Generally, two ounces of tea are used for each 1-xc2xd gallons of tea to be made. Cold mixing water is used to dilute the tea extract to make ice tea and hot mixing water is added to the extract to make hot tea.
A problem with the ground tea makers is that when the hot water is first added to the brew basket the air inside of the envelope heats and expands. This causes the envelope to expand and consequently to float on top of the hot water. When floating on top of the water the tea inside the envelope does not properly steep and the steeping water can exit the brew basket without passing through the tea envelope. Accordingly, filter baskets have been provided with inserts 24 that are designed to hold the envelope 26 down within the brew basket in a position directly above the drain hole 22. In this position at the bottom of the brew basket the envelope 26 and the tea contained within is kept submerged during steeping. Most but not all the water passes through the envelope to exit from the drain hole.
Disadvantageously, different sized (two ounces and four ounces) and different shaped (square, rectangular and round) commercial tea envelopes and the use of multiple envelopes for a single brew requires the use of different sized and different shaped inserts or different brew baskets with integrated inserts to hold the different envelopes in proper steeping position within the brew basket.
In the case of the tea leaves in an open filter, the tea leaves at first float on the surface of the hot water but then quickly saturate and sink into the water and steep and do not suffer from this problem. However, because of the need to accumulate hot water in the brew basket for several minutes, it is necessary to keep the drain hole 22 relatively small. Consequently, it is not uncommon for the tea leaves after wetted to collapse the filter paper to create a blockage over the drain hole 22 that interferes with proper draining.
The tea envelopes of ground tea are generally preferred over loose tea leaves because of the ease of use of the ground tea envelopes compared to the packages of loose tea leaves. If greater quantities of tea arc desired, then more two ounce envelopes 26 are added into the brew basket 18. The need for a separate filter paper required by the loose tea bags is eliminated, and thus the associated separate steps of inserting and removing the separate filter are eliminated. The closed filter envelopes 26 eliminate spillage, and the separate steps of opening the plastic package, dumping of the tea into the open filter and the disposal of the empty plastic package are also eliminated.
It has been determined that increased amounts of oxygen in the hot brew water during steeping improves the quality of the tea extract with respect to potency and flavor of the final tea product.
In accordance with the tea making method of the present invention, the need for using different sized inserts or brew baskets to brew tea from different sized or shaped tea envelopes is eliminated and increased free oxygen is put into contact with the tea during the extraction process by eliminating the process of steeping.
This objective is achieved in part by providing a method of brewing tea in an automatic tea maker having a supply of hot brew water, a controlled valve for passing the hot brew water into a brew basket, a supply of mixing water, and a dispensing urn for receipt of tea extract and receipt of mixing water from the mixing water supply, coposed of the steps of establishing with a timer of a controller a brew cycle, said brew cycle being composed of a plural succession of extraction cycles, each extraction cycle alternating between an intermittent add period of preselected duration and an intermittent pause period of preselected duration, placing dry tea ingredient at the bottom of the brew basket, opening the controlled valve during each add period to add hot water from the hot brew water supply to the tea at the bottom of the brew basket, and closing the controlled valve during each of the intermittent pause periods to allow the hot brew later added during the add period to drain sufficiently through the tea and out of the drain hole as tea extract to expose to atmospheric air the tea within the brew basket before the commencement of the next add period, and draining from the brew basket through a drain hole of sufficient size substantially all of the tea extract during each pause period.
Preferably, each of the extraction cycles has a period duration on the order of thirty seconds, and each of the add periods is on the order of approximately seven to ten seconds in duration. The method also may include the steps of preselecting the duration of the add periods for a given brew cycle to be one of a period on the order of an approximately seven seconds and a period on the order of approximately ten seconds.
In accordance with one aspect of the method of the invention, an amount of hot water on the order of approximately 6.33-7.6 ounces of hot brew water is added to the brew basket during an add period on the order of 7-10 seconds during each intermittent add period, and the drain hole has a minimum diameter on the order of approximately 0.285 inch. Generally, the duration of the brew cycle is on the order of approximately 5-6 minutes, the extraction cycle is approximately thirty seconds, the add period is approximately seven to ten seconds and the amount of hot brew water added to the brew basket during each add period is approximately 6.33-7.6 ounces.
The objective is also achieved by a method of making tea in an automatic tea maker having a supply of hot brew water, a controlled valve for passing the hot brew water into a brew basket, a supply of mixing water, and a dispensing urn for receipt of tea extract and receipt of mixing water from the mixing water supply, by performing the steps of placing a preselected amount of tea within the brew basket, during a brew cycle automatically passing a preselected quantity of hot brew water into the brew basket and into contact with the tea at the bottom of the brew basket at a preselected brew water passing rate, and draining tea extract from the brew basket at a preselected drain rate relative to the preselected brew water passing rate to prevent the tea from continuously steeping in its entirety in the hot water for the entire brew cycle and to thereby expose the tea to atmospheric air including oxygen during a significant portion of the brew cycle.
Preferably, the step of automatically passing includes the step of intermittently changing the relationship between the passing rate and the drain rate to allow a substantial portion of all of the tea extract to be drained from the brew basket repetitively throughout the brew cycle. The actual rate of passing during intermittent periods, when there is no pausing in the actual passing, is preferably greater than the drain rate, preferably approximately 3-4 times the drain rate.
In the preferred embodiment, the average passing rate during the brew cycle is composed of a plurality of successive periods of different actual rates that vary substantially above and below the average rate and the drain rate is continuous, and included is the step of intermittently changing the relationship between the passing rate and the drain rate to allow a substantial contact of the tea with the atmospheric oxygen during the brew cycle.